Solidified oils and methods of manufacture



Patented Dec. 7, 1948 SOLIDIF'IED OILS AND METHODS OF MANUFACTURE Alan Beerbower, Westfleld, and Harold A. Ricards, J13, Granford, N. .L, assignorsto Standard Oil Development Company, a corporation of Dela- .ware

' No Drawing. Application August 29, 1944,

Serial No. 551,772-

The present invention V relates to improvements in solidified oils which may be used for fuels or lubricants and more specifically to a stabilized solidified fuel and to an improved process for producing the same.

Thickened oils have been used for many years both as fuels and lubricants. For lubricating purposes the oils used are generally high boiling petroleum lubricating oils; These oils range from the lighter spindle oils to the heavier residuals such as cylinder stocks. For the manufacture of fuels, lighter, more readily vaporizable hydro carbons are used such as gasoline, naphthas, kerosene or even gas oils. The thickening or solidification is brought about through the oils of a thickening agent which is usually a soap, that is an alkaline soap such as a soda soap. The thickened lubricating oils are known as greases and in many cases are reasonably stable, but they are often unstable which by the dispersion u chime. (01. 252-42) imperfection is exhibited by a tendency to bleed oil and in bad cases actual separation of the soap from the oil occurs. This instability is more marked in the fuel compositions because of the use of less viscous oils in these compositions.

It is desired therefore to stabilize these compositions and it has been found that this can be done by incorporating in the grease a small amount of certain selected fatty oils. The action of these materials is not fully understood but it is believed that the fatty oil is saponified during the manufacture at least to some extent, but in any case the particular type and the amount of the fatty oil is highly critical.

In the manufacture of stabilized solidified oils, the preferred soap producing organic materials are the more saturated fatty acids, such as stearic, palmitic acids, etc., in mixture with rosin or abietic acid. The fatty acid is present in the larger proportion. The acids of saturated oils such as fully hydrogenated oils can be employed as well. To this acid mixture is added an equal amount of petroleum oil, which serves as a flux or solvent, and from one-third to twothirds, based on the weight of the fatty acid, of a selected fatty oil is then added. The nature of this selected fatty oil will be described more fully below. The mixture is melted together (this can be done even at room temperature, for example from 60 to 110 F., without difliculty) and it is then mixed with a substantial portion of the oil to be solidified. The entire amount of oil can be added at this point or, if desired, a smaller amount say one-fifth to one-third of the oil can be added, the remainder being added slowly from 2 time to time later. may be 30 to 110 F.

When the mass is thoroughly mixed, a sufflcient quantity of sodium hydroxide is then added for complete saponification of the fatty acids and also of the fatty oil which has been added. The soda is generally used in an aqueous solution of ture' is stirred together so that the soap is formed in the presence of the oil, that is to say in situ."

Saponification starts almost immediately and the main reaction primarily between the free acid and the soda is over in 10 to 30 minutes and the mixture gradually solidifies. Secondary reactions appear to occur for several hours or even days depending on the temperature of the operation and it is believed that the fatty oil addedis 'then slowly saponified. In any case, the material gradually hardens into a stable grease or paste which is smooth without any marked fibrous structure and is extremely stable on standing. It shows no bleeding even when the oil used is a light naphtha in which case the tendency toward bleeding and fuel separation is at its worst.

The selected fatty oil referred to generally above is an important ingredient in the above composition since its function is to stabilize the mixture. In general, it has been found that the fatty oils should contain a major amount of saturated fatty acids or unsaturated fatty acids which contain hydroxyl groups, and with only minor amounts of simple unsaturated acids such as oleic. In other words, fatty oils containing saturated fatty acids such as stearic, palmitic or the fully hydrogenated acids are preferred but hydroxy acids such as ricinoleic appear to be about equally good. Oleic acid, however, should be avoided and therefore most of the edible fats are not desirable for this purpose. Of the commercial raw materials, castor oil is extremely good because it contains only small amounts of oleic acid compounds and large amounts of ricinoleic. Similarly, hard tallows in which the oleic acid content is small can be used. Fats which have been hydrogenated to reduce the oleic acid content; may also be employed. These various materials are used in about one-third to' twothirds of the free acids which were added to make up the main quantity of the soap.

The petroleum oil makes up the balance of the composition and consists of from to 93% by weight of the entire mixture. The amount of water is ordinarily from 1 to 4% in the mixture and the remainder is made up of the soap and The temperature of the oil say 40 or 50% strength and the mix- 3 the free glycerin The greater the proportion of soap in the mixture, the harder the grease will be.

Example As an example of the present composition and its method of manufacture, the following materials were mixed at room temperature:

Parts by weight This mixture was gently heated to about 90 F. and melted together. About 85 parts of gasoline were then added. Saponification was accomplished at room temperature with the aid of two parts by weight of 40 to 50% 'caustic soda, and two parts of water were also added. The mixture was stirred at room temperature and set in about ten minutes but hardening appeared to continue fora period of some 48 hours while the material was left standing. The product was found to be a firm solid gel. It was easily softened by agitation but when left standing, the gel gradually reformed and hardened in the same manner in which the original hardening occurred. It wasextremely stable against bleeding and separation of the soap, and when ignited, it burned readily.

If the fatty oil is omitted from the above mentioned composition, the product is found to form quite well but subsequently separates almost completely.

The above mentioned product has a variety of uses. When made up with gasoline, it is a good canned fuel, which can be ignited with a match and burns with a steady flame so that it may be used to heat various cooking utensils and for other purposes. It may be used also as -a fuel in cigarette lighters and for similar deyices where small flames are employed. As a grease it is extremely stable and useful for rough work chiefly where moisture is not encountered.

We claim:

1. A stabilized, solidified mineral oil consisting essentially of a mineral oil gelled by a soap formed in situ from free saturated fatty acids, and stabilized by the saponification in situ of a fatty oil rich in esters selected from the group consisting of esters of saturated fatty acids and esters of hydroxylated unsaturated acids, said. fatty oil being added to the initial mixture in the proportion of A; to of the said free saturated fatty acids.

2. A stabilized, solidified mineral oil as in claim 1, wherein the said fatty oil consists principally of castor oil.

3. A stablized, solidified mineral oil as in claim 1, wherein the said mineral oil comprises 75 to 93% of the composition, the remainder being soap of the free fatty acids, the saponified fatty oil, glycerol and a minor proportion of water.

4. A stabilized, solidified mineral oil as in claim 1, wherein the said mineral oil consists principally of volatile hydrocarbons.

5. A stabilized, solidified mineral oil as in claim 1, wherein the said mineral oil consists primarily of kerosene.

6. A stablized, solidified mineral oil as in claim 1, wherein the said mineral oil consists primarily of gasoline.

7. A stabilized, solidified mineral oil consisting essentially of a mineral oil gelled by a soap formed in situ from free saturated fatty acids and stabilized by the saponification in situ of a fatty oil rich in esters selected from the group consisting of esters of saturated fatty acids and esters of hydroxylated unsaturated acids, said fatty oil being added to the initial mixture in the proportion of A to of the said free saturated acids, and a small quantity of rosin.

8. A stabilized, solidified mineral oil as in claim 1, wherein the said soap is a sodium soap.

9. A process for producing stable gelled oils which consists essentially of preparing a solution of a mineral oil, free saturated fatty acids and a fatty oil rich in the esters selected from the group consisting of esters of saturated fatty acids, and esters of hydroxylated unsaturated acids, said fatty oil being in the proportion of to of the said free saturated fatty acid, adding caustic soda to said solution maintained at room temperature, thereby forming a soap with the said fatty acids, and slowly saponifying the said fatty oil.

10. A process for producing stable gelled oils as in claim 9 wherein the said mineral oil conin the naphtha to kerosene range.

11. A process for producing stable gelled oils as in claim 9, wherein the said mineral oil is a normally liquid hydrocarbon boiling in the naphtha to kerosene range and comprises to 93% of the said solution, and the said fatty oil consists primarily of castor oil.

ALAN BEERBOWER. HAROLD A. RICARDS, JR.

REFERENCES CITED The following references are of record in the file of thispatent:

UNITED STATES PATENTS Number Name Date 1,266,080 Strobl May 14, 1918 1,484,190 Ray Feb. 19, 1924 1,863,962 Bierlich June 21, 1932 1,989,196 Hilliker Jan. 29, 1935 2,038,688 Taylor Apr. 28, 1936 2,049,072 Mikeska July 28, 1936 2,334,239 Barnett Nov. 16, 1943 2,380,960 Fraser Aug. 7, 1945 

